In the development of electronic injection molding machines, the large-scale requirement is one of the major trends thereof. If a traditional in-line injection frame is used in a large-scale electronic injection molding machine, a high power injection motor shall be firstly chosen to match the injection capability of the injection machine, however which will relatively greatly increase the volume and cost thereof. Secondly, during the course of injection, the in-line injection frame needs to drive the injection motor and/or meter motor of the injection move plate, so that the in-line injection motor needs to bear the movement momentum of the whole body of the injection frame, leading to a not good injection response and acceleration capability of the frame which affects the working efficiency thereof. Furthermore, because the in-line injection motor is used, the check ring on the in-line injection frame, during the course of injection, will cause an adverse flow of the plastic material which remarkably affects the precise of the injection amount. The technology of the electronic injection molding machine is disclosed in U.S. Pat. No. 5,421,712, No. 5,863,567 and No. 6,866,496.
As shown in FIG. 1 and FIG. 2, U.S. Pat. No. 5,421,712 discloses an in-line electronic injection frame, which employs the same injection rod to process injection and meter, wherein an injection motor 13 and a meter motor 14 are arranged on a moving plate 123 for respectively controlling the injection and meter of the injection rod. However, this prior art is configured to employ a single injection motor 13 which leads to an insufficiency of injection power, so that which can not meet the requirement of large-scale electronic injection machine. Furthermore, during the course of injection of this prior art, the injection motor 13 and meter motor 14 arranged on the moving plate 123 move together with the moving plate 123, the movement momentum is thus increased which affects the injection response and acceleration capability.
As shown in FIG. 3, U.S. Pat. No. 6,866,496 discloses a two-plate in-line electronic injection machine. The two-plate design successfully employs a plurality of parallel injection motors 317 to enhance the injection capability. However, the moving plate 313 is still configured to employ a meter motor 312, the problem of over high movement momentum of the injection frame, which affects the injection response and acceleration capability, is still can not be solved. Furthermore, during the course of injection, the check ring design of the in-line injection frame will also cause a adverse flow of the plastic material which affects the precise of the injection amount.
As shown in FIG. 4, U.S. Pat. No. 5,863,567 discloses a two-stage electronic injection machine, which respectively employs an injection rod and a meter screw to process injection and meter. During the course of injection, only the injection motor 468 move together with the transmission mechanism, thus the movement momentum there of is relatively small so that the injection response and acceleration capability thereof are slightly improved, yet there is still room for improvement. However, in this prior art, the single frame of the injection motor 468 can not meet the requirement of the injection capability of large-scale electronic injection machine either.
It can be learned from the above published prior arts that, in the electronic injection molding machine, the design adopting a single injection motor can not meet the injection capability requirements of large-scale injection machine. Furthermore, during the course of injection, the injection motor, or further the meter motor on the injection moving plate needs to be driven at the same time, thus the injection motor bears the movement momentum of the injection machine, which affects the injection response and acceleration capability, therefore the working efficiency thereof will be affected and power will be wasted. Simultaneously, because a single injection motor is adopted, during the course of injection, the check ring on the in-line injection frame will cause an adverse flow of the plastic material which affects the precise of the injection amount. Although U.S. Pat. No. 5,863,567 discloses that an injection rod and a meter screw are used to respectively process injection and meter, the problem of unsatisfied injection response and acceleration capability is still unsolved.
Consequently, how to solve the problem of the prior arts has become a take in this field.